<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script type="text/javascript">
        // 单行注释
        /*
        * 多行注释
        * 多行注释2
        * **/
        function sayHello() {
            alert("Hello");
        }

        "use strict"; //也可以指定函数在严格模式下执行
        function doSomethings() {
            "use strict";
        }
    </script>
    <script src="example.js" defer = "defer"/>
    <script src="http://bailang/afile.js"  defer = "defer" />



</head>
<body>

<!--这里显示内容-->

</body>
</html>